Revisiting the design of vertically polarized slotted waveguide array antenna

In this paper measured and simulated results for a slotted waveguide antenna array operating in the X-band and having vertical polarization with slots cut in a non conventional orientation was presented. Despite the fact that the literature reports that this kind of antenna exhibit low radiation efficiency, simulations showed that modifying the slot width the power radiated through the slot can be controlled. Therefore, modulating the slots width following a quarter sinusoidal law along the waveguide wall enabled obtaining a resonant waveguide antenna with the desired frequency bandwidth for a return loss better than 19 dB and with sidelobes below -20 dB. To the best of our knowledge, this is the first time that radiators like the one proposed here have been successfully designed.